Dental engine



(No Model.)

DENTAL ENGINE.

Patented Feb. 18

IlIIII ANDREW B.GRAHAM. motoumuwAsmNmou. n C

UNITE TATES *ATENT rFicE,

STEPHEN H. BROOKS, OF NEW YORK, N. Y., ASSIGNOR TO EDWARD A. PEIROE, OF SAME PLAOE, AND J. OTIS COX, OF BROOKLYN, NEXV YORK.

DENTAL ENGINE.

SPECIFICATION forming part of Letters Patent No. 555,035, dated February 18, 1896.

(No model.)

T at whom it may concern:

Be it known that I, STEPHEN H. BROOKS, a citizen of the United States, and a resident of the city, county, and State of New York, have invented certain new and useful Improvements in Dental Engines, of which the following is a specification.

My improvements refer to that class of dental engines embodying a horizontal drivingwheel and operated by the foot of the dentist.

The objects of the present invention are principally to so improve this class of engines as to make the same simple in construction and strong and durable, to protect the more delicate parts of the engine against accidental strokes and blows, to make it capable of being readily placed in such operative position as will be best suited to the particular work in hand, and of being folded into a small space when not in use. The means which I employ for accomplishing these and other useful objects are set forth in the following specification and claims.

In the accompanying drawings, forming part of this specification, Figure 1 represents a side elevation of an engine folded up compactly, as required for shipping purposes, and Fig. 2 shows a ground plan of the engine so unfolded as to make it ready for use by the operator, while Fig. 3 shows an end view of the standard to which the pedal mechanism is fulcrumed. Fig. 4 represents a vertical section through the lower part of the toolsupporting device embodying the tool-carrying standard and its supporting-base. Fig. 5 represents, on an enlarged scale, a joint between two telescoping sections of the toolstandard.

Corresponding numerals throughout the different views refer to corresponding parts.

is a grooved main driving-wheel, and 11 a broad base which carries the vertical axle 12 around which such wheel revolves, thus forming the wheel-support. From such support a curved standard 13 extends upward, and from such standard there branch out laterally two bars 14 and 15, the two together forming a continuous bar, and the bar 14 together with wheel-base 11 and standard 13 forming a bifurcated part of the engine-frame within which the wheel is mounted. To the free end of bar 14 there is attached a vertical pivot 16 (shown in the drawings) to be located directly above axle 12 of wheel 10.

17 is a base for the standard 22 carrying the shaft for operating the dental tool. Such base together with the standard forms the tool-support.

Base 17 rests upon the floor when the engine is in operation, so as to provide a reliable support for the tool and its shaft.

18 is a bar rotatably connected with the engine-frame by being attached to pivot 16, so as to be capable of swinging horizontally around the same and to preferably pass above and clear bar 14 15. The other end of bar 18 is provided with an eye engaging with the outside of the base of the tool-carrying standard, whereby it becomes possible to swing said base around the engine-frame, such eye being so flattened as to always insure the same relative positions between the horizontal main driving-wheel and small guide-pulleys 19 19 on such standard-base, the driving-cord 20 being made to pass around said driving-wheel and guide-pulleys and around small drivingpulley 21 after tool-standard 22, and with it said pulley, have been placed in their operative elevated position for the purpose of rotating a flexible tool-shaft engaging with said pulley 21.

23 is a base from which extends upward a standard 24 terminating on top in a horizontal flange 25, which is rigidly connected with and forms the continuation of bar 15.

26 is a horizontal pivot projecting from standard 24. Said pivot forms the fulcrum for bell-crank lever 27, which is a part of the pedal mechanism of the engine.

Base 23 with standard 24 forms the pedalsupport, and it will therefore be seen that in my engine swinging bar 18 is mounted on a rigid frame embodying both the wheel-support and the pedal-support. The end of the upper arm of bell-crank lever 27 contains a ball 28 within a suitable socket.

29 is a pitman to the outer end of which such ball is attached, the inner end of the pitman terminating in the usual manner in a crank-pin 30 attached to the main drivingwheel. The lower arm of bell-crank lever 27 is connected with the treadle 31 in the usual manner by a link 32, having balls at both ends fitting in proper sockets in said bellcrank lever and said treadle. Treadle 31 is pivoted at to treadle-bar 34, which extends to base 23 and is pivotall y secured to a vertical pin 35 on said base. Under this arrangement it is possible to swing the treadle horizontally around said pin and base 233, to which it is attached, so as to bring it into a position convenient for the foot of the operator. hen the engine is to be shipped the treadle-base and with it the trcadle may be swung into the position shown in Fig. 1, so as to place the same underneath bar 15 and to bring the unsupported end of the treadlebase directly underneath standard 153.

36 is an eye in the upper end of said standard, where the same joins bar 14 15. litman 29 operates within said eye and underneath bar 1% 15, such bar being made broad enough to substantially cover it whatever position it may assume while actuating the driving wheel. Thus it will be seen that the rigid engine-frame embodying the wheel-support and the pedal-support, as devised by me, while being simple and strong also affords protection to the working parts connected therewith, whether the engine be in use or packed for transportation.

It is important to so arrange the engine and the mutual relation of its parts as to avoid the danger of the pitman accidentally coming in contact with the legs of a dental chair under which the engine may be placed. For this purpose and in order to provide a simple and compact structure I place such pitinan in an elevated position above the horizontal main driving-wheel. This also enables me to give such pit-man a very simple form, as shown, making it of a straight bar of wrought-iron. or steel.

A bar 37 projects from the engine-frame at an angle of about one hundred and twenty degrees with the bar ll 15 and has attached to its outer end spiral spring 15S,whieh latter also connects at its other end with the end of pitman 29. Said spring serves to carry such pitman over dead centers in the usual manner.

It is desirable to be able to tilt the toolcarrying standard toward the wheel-frame and into a position parallel with and close to swinging bar 18, so as to fold together the engine into a compact form when the same is not required for use, and particularly when it is to be placed into a casing for transportation. For such purpose I construct the up per end of tool-standard base 17 in the form of a tube, within which is fitted a pin or post 2-59 resting within such tube on a spiral spring 40. The upper end of post 39 forms a wedge shaped latch engaging with a notch 41 in the lower part of foot-piece 42, forming part of tool-carrying standard 22 when such standard is in an upright position. At the upper extremity of the standard-base there are provided two lugs 43 43, between which foot piece 42 is pivotally connected. The spiral spring 4:0 has a tend ency to force post 35) upward and to secure operative contact between its head, forniinga latch and the notch in said foot-piece. It also, when the standard is being placed in an inclined position, and particularly while it is being folded down toward the bar connecting the standard-base with the engine-frame, will press post 39 against the edge of such footpiece and will thereby pre vent the standard from. abruptly falling over toward said bar, thus serving as a brake on such occasion.

The tool-carrying standard I prefer to construct in sections and telescoping, and when said standard is drawn out 1 secure the end of the inner tube to that of the enter one by a clutching device constructed as follows:

The upper end of outer tube, 44, is provid ed with spring-jaws 45 45. Near their ends said jaws are provided with a circular ridge 4-6, extending outward from the general cylindrical surface of such section. The extreme ends of such jaws are turned inwardly. 47 indicates a screw-thread provided on the outside of tube ti underneath such spring-jaws.

48 is a coupling-sleeve provided on its inner surface and at its lower end with a screw thread adapted to engage with the screwthread on tube 44, its inner surface near the upper end being contracted sufficiently to force together said spring-jaws and cause the same to securely grip and hold the lower end of inner tube, 4.0, after the same has been drawn out of tube at sufficiently.

I do not propose to confine myself to placing the independent axle for swinging bar 1 8 directly above the axle of the driving-wheel, as .it will readily be seen that such axles may be placed eccentric with reference to each other, provided any one of the well-known devices for tightening and loosening the drivin g-cord be used to give such cord the proper tension in accordance with the temporary distance between the axle of the driving-wheel and the tool-carrying standard.

I am aware that it is not new to employ in a dental engine having a horizontal drivewheel a swinging rod or bar connecting the tool-support with the driving-wheel frame so as to make such bar rotate around said frame, and as I also know it to be a common practice to attach to the outer end of a bar rotating around the axle of the drive-wheel a base supporting the tool-standard on the floor I do not claim herein broadly a swingingbar pivotally connected to the wheel-frame and also connected to a tool-standard base resting on the floor.

I claim as new and desire to secure by Letters Patent- 1. In a dental engine, in combination with the wheelsupport and the pedal-support, an intermediate bar rigidly connecting the same, a horizontal driving -wheel, and its pedal.

mechanism, the treadle-bar being at one end pivotally connected to the pedal-base and having a free end adjusted to swing underneath such intermediate bar, substantially as set forth.

2. In a dental engine, in combination with the engine-frame comprising the wheel-support and the pedal-support and a bar connecting the same, and ahorizontal main driving- Wheel, pedal mechanism for operating such Wheel, the part of the pit-man of the pedal mechanism adjoining the wheel being placed above such wheel and underneath said connecting-bar, substantially as set forth.

- 3. In a dental engine, the combination with a horizontal dri ving-wheel and its supportingframe, of a tool-support, a bar secured to the tool-support at one end and pivotally connected With the wheel-supporting frame at the other end, pedal mechanism secured to a suitable standard and a bar rigidly connecting such standard with the Wheel-frame and placed above the pedal mechanism, substantially as set forth.

4. In a dental engine, the combination with a horizontal wheel, of the wheel support,

pedal mechanism for operating the Wheel, the pedal-support to which such mechanism is fulcrumed, a bar rigidly connecting such supports and containing an eye Within which the pitmanoperates, the tool-support, and a bar connecting with the tool-support at one end and having its other end pivotally secured to the rigid frame comprising the Wheel-support and the pedal-support, substantially as set forth.

5. In a dental engine, the combination with the pedal-base 23 and its standard 24, of a lateral flange, as 25, a bar connecting the pedalsupport with the Wheel-support, and pedal mechanism in engagement with the Wheel, the bell-crank lever of the pedal mechanism being fulcrumed underneath such flange, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name, in presence of two witnesses, this 16th day of August, 1898.

STEPHEN H. BROOKS.

Witnesses:

CHAS. L. HoRAcK, CHAs. B. BARBER. 

